1. Field of the Invention
The present invention generally relates to a semiconductor memory device, and more specifically, to a technology of generating a control signal for regulating a potential of an internal power voltage when an extended mode register is set, thereby easily adjusting an operating speed and a tWR (time to write recovery) of a chip.
2. Description of the Related Art
Generally, a semiconductor memory device enters into a specific mode other than a normal mode through a mode register set (hereinafter, referred to as “MRS”).
FIG. 1 is a diagram illustrating a conventional semiconductor memory device.
The conventional semiconductor memory device comprises a normal address generating unit 10 for generating normal addresses A1˜An, a bank address generating unit 20 for generating bank addresses B1˜Bn, a command generating unit 30 for generating commands such as a MRS command control signals MRS_control, a EMRS command control signals EMRS_control, a MRS 40 for setting a plurality of modes and an extended mode register set (hereinafter, referred to as “EMRS”) 50.
The MRS 40 defines operation modes of a DRAM and a SDRAM on a basis of information such as a burst length, a CAS latency and an operating mode. The MRS 40 is programmed by the MRS command control signals MRS_control, and programs stored information again or maintains the information until a power source of the device is turned off.
The EMRS 50 is operated in the similar way to that of the MRS 40, and sets a specific mode other than modes set in the MRS 40.
In the above-described conventional semiconductor memory device which is completed as a package, a predetermined potential of an internal power voltage is maintained even an external power voltage is increased.
To speed up the semiconductor memory device completed as a package, if necessary, the internal power voltage is required to rise. However, after the semiconductor memory device is completed as a package, the potential of the internal power voltage cannot be changed even when the external power voltage is increased.